Valence Bond Theory (VBT) and Molecular Orbital Theory (MOT) have the following common features:
1. The Basic principle is same in both the theories. Both involve distribution of electrons. Thus whether it is atomic or molecular cannot have more than two electrons.
2. Both the theories include the sharing of electrons by the nuclei.
3. According to both the theories the energy of overlapping orbitals must be comparable and there must be similarities in their symmetry.
Valence Bond Theory (VBT)
Molecular Orbital Theory (MOT)
|Bonds are localized to two atoms not molecule.||Bonds are localized to two atoms as well as molecule.|
|Valence orbital theory was first proposed by W.Heitler and F.London in 1927.||Molecular orbital theory was proposed by F. Hund and R.S. Mulliken in 1932.|
|Resonance plays an important role in this theory.||There is no place of resonance in this theory.|
|There is no explanation of paramagnetic character of oxygen.||Satisfactory explanation of paramagnetic character of oxygen.|
|Calculations are simpler.||Calculations are very tedious.|